Appliqués and other design articles are widely used for a variety of decorative applications. Appliqués are generally design articles, such as patches, that are adhered or fastened to a substrate, such as a textile. Processes involving embroidery, screen-printing and flocking, conventionally manufacture Appliqués.
Embroidered appliqués are made by stitching designs with thread onto a fabric base material and then cutting the appliqué out of the material. Later stitching can be added to the edge of the material for a more finished-looking product. Examples of embroidered appliqués are disclosed in U.S. Pat. Nos. 3,657,060 and 3,816,211. Embroidered appliqués suffer from disadvantages including being expensive, labor intensive and slow to produce. Looms generally produce embroidered appliqués. It is also difficult or impossible to achieve a fine detail in the designs because of the limitations in the stitching process.
Screen-printed appliqués are made by screen-printing textile inks directly onto a textile and cutting out the appliqué. In the alternative, a pre-cut textile appliqué, with or without a stitched edge, can be screen-printed. Screen printed appliques are perceived as being an inferior product relative to an embroidered applique because they can lack three-dimensionality, rich texture, brilliant appearance, and wash-fastness.
Flocked appliqués are made by screen printing a flocking adhesive onto a substrate, applying flock fibers to the adhesive by vibration, gravity or electrostatic discharges, drying the flocked adhesive, vacuum cleaning excess flock fibers from the flocked adhesive, cutting the resulting appliqué into a desired shape, and optionally stitching the edge for a finished look.
There are two methods of applying flock to a substrate. The first method is referred to as direct flocking, and the second method is referred to as flock transfers.
In direct flocking, the flock is applied directly to the substrate that forms the finished product. Usually wallpaper, carpets and decorative elements of garments are produced in this manner. An example of direct flocking is found in U.S. Pat. No. 3,793,050. This particular direct flocking method allows the use of different color or size of flock in the same design surface to be flocked. Each color of flock is passed through a screen that restricts the color to the desired part of an adhesive layer. A multicolor flock design is thus obtained on the surface of the substrate being flocked.
Multicolor direct flocking can have a number of disadvantages. It is an exacting procedure with many variables to be controlled requiring specialized flocking equipment and an environment that is controlled for relative humidity. During startup, many reject-quality articles may result as the process variables are adjusted by trial and error until the desired result is found. Further, if the article to be decorated has an uneven surface like many textiles, then density of the flock, control, speed and the quality of the finished design, i.e., sharpness of lines separating colors, vivid images, etc., can be adversely affected.
In transfers, the flocked design is bonded in reverse to a release sheet by means of a temporary release adhesive coating. The flock can be colored with different color inks and coated with a binding layer and hot melt adhesive in a desired reverse image. The transfers are applied to articles using heat and/or pressure. The release sheet is then peeled away leaving a finished decorative design. Examples of transfers are described in U.S. Pat. Nos. 4,810,549; 5,207,851; 5,047,103; 5,346,746; 5,597,637; 5,858,156; 6,010,764; 6,083,332; and 6,110,560; in copending U.S. patent application Ser. Nos. 09/548,839; 09/621,830; 09/629,746; and 09/735,721; and in EP 0 685 014.
Various techniques have been developed to produce flocked transfers. The process of U.S. Pat. No. 4,810,549, for example, forms a design by screen printing a transfer release adhesive onto a primary carrier, screen printing successive colors of flock onto the transfer release adhesive in desired patterns, screen printing the protruding tips of the flock with a water-based acrylic binder (40–60% water), applying a nylon polyester hot melt adhesive to the acrylic binder, and heating the design to cross link the binder and the adhesive. The process of EPO 685,014 first applies a base layer of plastic sheet material to the entire surface of the primary carrier, second selectively applies an adhesive to regions of the base layer through an image screen, third applies flock fibers to the base layer through the image screen, and finally high frequency welds the base layer to the desired substrate.
Flock transfers and the conventional methods for manufacturing them can have a number of disadvantages. First, the transfers are relatively expensive to manufacture and/or difficult to manufacture in high volumes. Second, the manufacturing methods are relatively complex and require a substantial capital investment. Third, the transfers require the release sheet to remain in place until after cooling and solidification of the adhesive and application to the substrate due to the poor strength of the permanent adhesive layer. Fourth, the manufacturing methods require undesired, flocked areas (like the center of the letter “O”) to be eliminated by being cut and/or picked out. Fifth, the use of a thermoplastic (hot melt) adhesive, such as polyester, leads to problems with higher operating costs, greater unit production times, and other problems associated with drying, removing excess material, and curing adhesives. Sixth, the process of EPO 685,014 requires (in addition to the primary carrier) a plastic base layer to support the resin film. This process is undesirable in that two separate layers, namely the base layer and adhesive layer, are deposited rather than the single layer.